In “World Cancer Report 2014”, the World Health Organization (WHO) reported that in 2012, there were already 14 million cancer patients worldwide, and it was estimated that the number of cancer patients would increase to 19 million by 2025, to 24 million by 2035. In 2012, there were 3.07 million cancer patients added in China, causing about 2.2 million deaths, accounting for 21.9% and 26.8% of the global amounts, respectively. In China, one in five deaths dies from cancer. Cancer becomes a second biggest killer next only to cardiovascular disease, seriously threatening human health. In recent years, as the development of the study on tumor biology, receptor tyrosine kinase has become a target for the research and development of antitumor drugs due to its important role in tumorigenesis, development and drug resistance.
c-Met, an important member of the receptor tyrosine kinase family, is highly expressed in most cancers and partial sarcomas, and is closely related to poor prognosis, such as lung cancer, breast cancer, colon cancer, prostate cancer, pancreatic cancer, stomach cancer, liver cancer, ovarian cancer, kidney cancer, glioma, melanoma and the like. c-Met induces cell proliferation, invasion, migration, and inhibits apoptosis as well as promotes angiogenesis by activating intracellular tyrosine kinases through interacting with its ligand HGF/SF or other pathways, thus playing an important role in the process of tumorigenesis and tumor development. Unlike other kinases, c-Met, a key node in tumor signaling network pathways, may interact with other tumor-associated molecules on cell surface to crosslinkingly activate and amplify tumor-associated effects, greatly promoting tumorigenesis, development and metastasis. The results show that 20% of acquired resistance of epidermal growth factor inhibitor (EGFR-TKIs) is closely related to the amplification of Met gene; combination of Met inhibitor and EGFR inhibitor can delay acquired drug resistance of EGFR-TKIs, and extend its clinical life. Therefore, targeting c-Met/HGF pathway has become a new and notable strategy for the treatment of cancer, and thus the research on chemical blocking c-Met signaling pathway, especially on anti-cancer drugs like small molecule c-Met kinase inhibitor, has currently become a hot spot in the field of cancer treatment. To date, 17 small molecule c-Met inhibitors have been or are in clinical trials, among them, PF-2341066 (Crizotinib), a dual kinase inhibitor of ALK/c-Met with high selectivity, had been approved by FDA for the treatment of non-small cell lung with positive ALK fusion gene in 2011; XL184/BMS907351, a multi-kinase inhibitor for Met, VEGFR-2, RET and the like, had been approved for the treatment of medullary thyroid carcinoma by the end of 2012. Although these kinase inhibitors have shown clinically superior targeting effect during the treatment, the occurrence of tumor resistance mutations has greatly diminished the effectiveness of these drugs during long-term treatment. The similarity of chemical structures also aggravates the cross-resistance of kinase inhibitors. On the other hand, although there is no direct evidence that specific kinase inhibitors are superior to multiple kinase inhibitors, the selectivity of kinases is closely related to off-target effects. Therefore, the discovery of pilot compounds with new structure and new mechanism currently becomes a new trend in the development of anti-tumor drugs targeting c-Met kinase.